<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>7</title>
</head>
<body>
    <script>
        var obj = new Object();
        obj.species = '动物';
        function Animal() {

        }
        // Animal.prototype.species = '动物';
        Animal.prototype = obj;
        function Person() {

        }
        Person.prototype = new Animal();

        var su = new Person();
        console.log(su.species, su.__proto__.__proto__.species, su.toString());
    </script>
</body>
</html>